Obesity and gastrointestinal cancer
Br J Surg 2010; 97: 628-42
This review summarises the evidence for the link between obesity and GI cancer.
The authors found that numerous studies consistently identified an association between oesophageal and colorectal carcinoma in the obese, though the link with other GI cancers is less robust.
The association is believed to occur because fat is a metabolically active tissue, and exerts systemic endocrine effects.
Another possible explanation for the increased risk of oesophageal cancer is reflux, which is more common in the obese, and which may cause Barrett's oesophagus.
Mortality from colorectal cancer increases with obesity, and in men with a BMI of 35-39.9 it is 1.84, and in women 1.36. A similar trend is seen in oesophageal cancer.
The authors conclude that tackling obesity may result in a lower incidence of GI cancers in future. Unfortunately, they make no suggestions about how this might be achieved.
Adult psychiatric outcomes of girls with ADHD
Am J Psychiatry 2010; 167: 409-17
ADHD is more common in boys, therefore most follow-up studies are carried out in males. The authors of this study hoped to ascertain whether a diagnosis of ADHD in childhood predisposed to psychological difficulties later in life in girls.
A longitudinal case controlled study of 140 six to 18-year-old girls with a diagnosis of ADHD and 120 girls without ADHD was conducted. At the 11-year follow up, 96 (69 per cent) of the ADHD group and 91 (75 per cent) of the control group were reassessed. The median age was now 22 years.
It was found that lifetime and one-year risks for a number of psychopathologies were higher in the ADHD group.
Lifetime hazard ratios were: 7.2 for antisocial disorders, 6.8 for mood disorders, 2.1 for anxiety disorders, 3.2 for developmental disorders, 2.7 for addictions and 3.5 for eating disorders. These findings are similar to those in boys.
Inhaled corticosteroids versus montelukast in children with asthma
Arch Dis Child 2010; 95: 365-70
The object of this study was to compare the efficacy of inhaled corticosteroids with montelukast in children with mild-moderate asthma.
The authors identified 18 studies (3,757 patients) which compared these two drugs. The primary endpoint was asthma exacerbation requiring systemic corticosteroids.
Children using inhaled steroids showed a significantly lower risk of exacerbations than those on montelukast (risk ratio 0.83). Pulmonary function was better in these children, as were several of the other secondary endpoints indicating asthma control. The authors conclude that inhaled steroids are better than montelukast in controlling asthma in young people.
Protein pump inhibitors and risk for recurrent Clostridium difficile infection
Arch Intern Med 2010; 170(9): 772-8
The aim of this American retrospective cohort study was to determine the association between PPI use and the risk of recurrent C difficile infection. Data were obtained from the New England Veterans healthcare system from October 2003 to September 2008.
The authors identified 1,166 patients who had received metronidazole or vancomycin for C difficile infection. Of these, 527 (45.2 per cent) had received oral PPIs within 14 days of diagnosis.
It was found that recurrent C difficile was more common in patients on PPIs than those not taking these drugs (25.2 versus 18 per cent).
Risks were higher in those over 80 and those receiving other antibiotics. The conclusion was that PPI use during treatment for C difficile is associated with a 42 per cent increased risk of recurrence.
The authors question the use of PPIs during treatment for C difficile, especially as they may be prescribed without clear indications.
What reduction in BMI is required to improve body composition and metabolic health?
Arch Dis Child 2010; 95: 256-61
It is known that weight loss of 5 per cent of body weight or more has been shown to give long-term health benefits.
With the present obesity epidemic among young people, the authors' aim was to ascertain what reduction in BMI would provide similar benefits in this group.
In a prospective cohort study from Bristol, 88 adolescents with mean BMI standard deviation score (SDS) of 3.23 (40 males, 96 per cent Caucasian, median age 12.4 years) attending a hospital obesity clinic were assessed for BMI, body composition, glucose tolerance, lipid profile, C reactive protein and BP.
Reducing BMI SDS by >0.5 achieved significant improvements in body fat, waist circumference and lipid profile. Even a reduction of 0.25 improved insulin sensitivity and lipid profile.
The conclusion is that significant improvements are seen with reduction of BMI by >0.5 SDS, while greater improvements occur if this weight loss is exceeded.
This shows again that small relative weight loss gives major health benefits, though with the very obese this will require a fairly major weight reduction.
- Dr Glenesk is a GP trainer in Aberdeen and a member of our team who regularly review the journals.
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